U.S. patent application number 10/683150 was filed with the patent office on 2005-04-14 for fuel storage devices and apparatus including the same.
Invention is credited to Clark, James E., deVos, John A..
Application Number | 20050079128 10/683150 |
Document ID | / |
Family ID | 34422673 |
Filed Date | 2005-04-14 |
United States Patent
Application |
20050079128 |
Kind Code |
A1 |
deVos, John A. ; et
al. |
April 14, 2005 |
Fuel storage devices and apparatus including the same
Abstract
A fuel storage device in accordance with a present invention
includes a fuel storage area and at least one of a fuel heater, a
byproduct heater and a valve.
Inventors: |
deVos, John A.; (Corvallis,
OR) ; Clark, James E.; (Albany, OR) |
Correspondence
Address: |
HEWLETT PACKARD COMPANY
P O BOX 272400, 3404 E. HARMONY ROAD
INTELLECTUAL PROPERTY ADMINISTRATION
FORT COLLINS
CO
80527-2400
US
|
Family ID: |
34422673 |
Appl. No.: |
10/683150 |
Filed: |
October 9, 2003 |
Current U.S.
Class: |
423/658.2 ;
206/.7; 429/436; 429/443; 429/506; 429/515 |
Current CPC
Class: |
Y02E 60/50 20130101;
H01M 8/04014 20130101; H01M 8/04089 20130101; H01M 8/04074
20130101 |
Class at
Publication: |
423/658.2 ;
429/017; 206/000.7 |
International
Class: |
B65D 085/00 |
Claims
We claim:
1. A fuel storage device, comprising: a fuel storage area; a fuel
outlet; and a fuel heater having an inlet operably connected to the
fuel storage area and an outlet operably connected to the fuel
outlet.
2. A fuel storage device as claimed in claim 1, further comprising:
a pressurizer associated with the fuel storage area.
3. A fuel storage device as claimed in claim 1, wherein the fuel
storage area is defined by a flexible container.
4. A fuel storage device as claimed in claim 1, wherein the fuel
outlet comprises a self-sealing connector.
5. A fuel storage device as claimed in claim 1, wherein the fuel
heater comprises a heat exchanger.
6. A fuel storage device as claimed in claim 5, wherein the heat
exchanger includes a connector through which heat from an outside
source is transferred to the heat exchanger.
7. A fuel storage device as claimed in claim 5, wherein the heat
exchanger includes a plurality of heat transfer fins.
8. A fuel storage device as claimed in claim 1, wherein the fuel
heater comprises a resistive heater.
9. A fuel storage device as claimed in claim 1, further comprising:
a byproduct storage area.
10. A fuel storage device as claimed in claim 9, further
comprising: a byproduct inlet operably connected to the byproduct
storage area.
11. A fuel storage device as claimed in claim 10, further
comprising: a byproduct heater having an inlet operably connected
to the byproduct inlet and an outlet operably connected to the
byproduct storage area.
12. A fuel storage device as claimed in claim 9, wherein the
byproduct storage area is defined by a flexible container.
13. A fuel storage device as claimed in claim 10, wherein the
byproduct inlet comprises a self-sealing connector.
14. A fuel storage device, comprising: a fuel outlet; means for
storing fuel; means for receiving energy from an outside source and
transferring heat to the fuel as the fuel flows from the means for
storing fuel to the fuel outlet.
15. A fuel storage device as claimed in claim 14, further
comprising: means for storing byproduct.
16. A fuel storage device as claimed in claim 15, further
comprising: a byproduct inlet operably connected to the means for
storing byproduct.
17. A fuel storage device as claimed in claim 16, further
comprising: means for receiving energy from an outside source and
transferring heat to the byproduct as the byproduct flows from the
byproduct inlet to the means for storing byproduct.
18. An electrochemical device, comprising: an electrochemical cell;
and a fuel storage device including a fuel storage area, a fuel
outlet operably connected to the electrochemical cell, and a fuel
heater having an inlet operably connected to the fuel storage area
and an outlet operably connected to the fuel outlet.
19. An electrochemical device as claimed in claim 18, wherein the
electrochemical cell comprises a direct methanol fuel cell.
20. An electrochemical device as claimed in claim 18, wherein the
fuel storage device is removably connected to the electrochemical
device.
21. An electrochemical device as claimed in claim 18, further
comprising: a pressurizer associated with the fuel storage
area.
22. An electrochemical device as claimed in claim 18, wherein the
fuel storage area is defined by a flexible container.
23. An electrochemical device as claimed in claim 18, wherein the
fuel heater comprises a heat exchanger.
24. An electrochemical device as claimed in claim 23, wherein the
heat exchanger is thermally connected to the electrochemical
cell.
25. An electrochemical device as claimed in claim 23, wherein the
heat exchanger is thermally connected to the electrochemical cell
by a heat pipe.
26. An electrochemical device as claimed in claim 18, wherein the
fuel heater comprises a resistive heater.
27. An electrochemical device as claimed in claim 18, further
comprising: a byproduct storage area; and a byproduct inlet
operably connected to the electrochemical cell and to the byproduct
storage area.
28. An electrochemical device as claimed in claim 27, wherein the
byproduct storage area is defined by a flexible container.
29. An electrochemical device as claimed in claim 27, further
comprising: a byproduct heater having an inlet operably connected
to the byproduct inlet and an outlet operably connected to the
byproduct storage area.
30. An electrochemical device as claimed in claim 27, wherein the
byproduct inlet comprises a self-sealing connector.
31. An electrochemical device as claimed in claim 18, wherein the
fuel outlet comprises a self-sealing connector.
32. A device, comprising: an apparatus that consumes electrical
power; an electrochemical cell operably connected to the apparatus;
and a fuel storage device including a fuel storage area, a fuel
outlet operably connected to the electrochemical cell, and a fuel
heater having an inlet operably connected to the fuel storage area
and an outlet operably connected to the fuel outlet.
33. A device as claimed in claim 32, wherein the electrochemical
cell comprises a direct methanol fuel cell.
34. A device as claimed in claim 32, wherein the fuel storage
device is removable.
35. A device as claimed in claim 32, wherein the fuel storage
device includes a pressurizer associated with the fuel storage
area.
36. A device as claimed in claim 32, wherein the fuel heater
comprises a heat exchanger.
37. A device as claimed in claim 36, wherein the heat exchanger is
thermally connected to the electrochemical cell.
38. A device as claimed in claim 32, wherein the fuel heater
comprises a resistive heater.
39. A device as claimed in claim 32, wherein the fuel storage
device includes a byproduct storage area and a byproduct inlet
operably connected to the electrochemical cell and to the byproduct
storage area.
40. A device as claimed in claim 39, further comprising: a
byproduct heater having an inlet operably connected to the
byproduct inlet and an outlet operably connected to the byproduct
storage area.
41. A device as claimed in claim 32, wherein the apparatus that
consumes electrical power comprises a processor.
42. A method of supplying a fuel to a fuel consuming device,
comprising the steps of: connecting a fuel storage device to the
fuel consuming device; and transferring heat from the fuel
consuming device to the fuel as the fuel exits the fuel storage
device.
43. A method as claimed in claim 42, wherein the step of
transferring heat from the fuel consuming device to the fuel
comprises transferring heat from the fuel consuming device to the
fuel with a heat exchanger as the fuel exits the fuel storage
device.
44. A method as claimed in claim 42, further comprising the steps
of: generating byproduct with the fuel consuming device; and
transferring heat from the fuel consuming device to the byproduct
as the enters the fuel storage device.
45. A fuel storage device, comprising: a byproduct storage area; a
byproduct inlet operably connected to the byproduct storage area; a
pressurized fuel storage area; a fuel outlet; and a valve having a
valve inlet operably connected to the pressurized fuel storage area
and a valve outlet operably connected to the fuel outlet.
46. A fuel storage device as claimed in claim 45, wherein the
byproduct storage area and the fuel storage area are separated by a
movable wall.
47. A fuel storage device as claimed in claim 45, wherein at least
one of the byproduct storage area and the fuel storage area is
defined by a flexible container.
48. A fuel storage device as claimed in claim 45, wherein at least
one of the byproduct inlet and the fuel outlet comprises a
self-sealing connector.
49. A fuel storage device as claimed in claim 45, wherein the
pressurized fuel storage area is pressurized by a spring.
50. A fuel storage device as claimed in claim 45, wherein the
pressurized fuel storage area is pressurized by a device located in
the byproduct storage area.
51. A fuel storage device as claimed in claim 45, further
comprising: a connector operably connected to the valve and
configured to allow the valve to be controlled by a remote
device.
52. A fuel storage device as claimed in claim 51, wherein the
connector comprises an electrical connector.
53. A fuel storage device, comprising: a byproduct inlet; means for
storing byproduct operably connected to the byproduct inlet; a fuel
outlet; means for storing pressurized fuel; and means for metering
the fuel operably connected to the means for storing pressurized
fuel and to the fuel outlet.
54. A fuel storage device as claimed in claim 53, further
comprising: means for heating the pressurized fuel.
55. A fuel storage device as claimed in claim 53, wherein at least
one of the byproduct inlet and the fuel outlet comprises a
self-sealing connector.
56. An electrochemical device, comprising: an electrochemical cell;
and a fuel storage device including a byproduct storage area
operably connected to the electrochemical cell, a pressurized fuel
storage area operably connected to the electrochemical cell, a
valve having a valve inlet operably connected to the pressurized
fuel storage area and a valve outlet operably connected to the fuel
outlet.
57. An electrochemical device as claimed in claim 56, wherein the
electrochemical cell comprises a direct methanol fuel cell.
58. An electrochemical device as claimed in claim 56, wherein the
fuel storage device is removably connected to the electrochemical
device.
59. An electrochemical device as claimed in claim 56, wherein the
byproduct storage area and the fuel storage area are separated by a
movable wall.
60. An electrochemical device as claimed in claim 56, wherein at
least one of the byproduct storage area and the fuel storage area
is defined by a flexible container.
61. An electrochemical device as claimed in claim 56, wherein the
pressurized fuel storage area is pressurized by a spring.
62. An electrochemical device as claimed in claim 56, wherein the
pressurized fuel storage area is pressurized by a device located in
the byproduct storage area.
63. An electrochemical device as claimed in claim 56, further
comprising: a connector operably connected to the valve and
configured to allow the valve to be controlled by a remote
device.
64. An electrochemical device as claimed in claim 63, wherein the
connector comprises an electrical connector.
65. A device, comprising: an apparatus that consumes electrical
power; an electrochemical cell; and a fuel storage device including
a byproduct storage area operably connected to the electrochemical
cell, a pressurized fuel storage area operably connected to the
electrochemical cell, a valve having a valve inlet operably
connected to the pressurized fuel storage area and a valve outlet
operably connected to the fuel outlet.
66. A device as claimed in claim 65, wherein the apparatus that
consumes electrical power comprises a processor.
67. A device as claimed in claim 65, wherein the electrochemical
cell comprises a direct methanol fuel cell.
68. A device as claimed in claim 65, wherein the fuel storage
device is removably connected to the electrochemical device.
69. A device as claimed in claim 65, wherein the byproduct storage
area and the fuel storage area are separated by a movable wall.
70. A device as claimed in claim 65, wherein at least one of the
byproduct storage area and the fuel storage area is defined by a
flexible container.
71. A device as claimed in claim 65, wherein the pressurized fuel
storage area is pressurized by a spring.
72. A device as claimed in claim 65, wherein the pressurized fuel
storage area is pressurized by a device located in the byproduct
storage area.
73. A device as claimed in claim 65, further comprising: a
connector operably connected to the valve and configured to allow
the valve to be controlled by a remote device.
74. A device as claimed in claim 73, wherein the connector
comprises an electrical connector.
Description
BACKGROUND OF THE INVENTIONS
[0001] 1. Field of the Inventions
[0002] The present inventions are related to fuel storage devices
that may be used, for example, in combination with fuel cells.
[0003] 2. Background
[0004] Many devices are fueled by fuel that is stored in a fuel
cartridge or other fuel storage device. Although the present
inventions are not limited to fuel storage devices that are used in
conjunction with any particular type of fuel consuming device, fuel
cells are one example of a device that may consume fuel stored in a
fuel storage device, and the present inventions are discussed in
the context of fuel cells for illustrative purposes only. Fuel
cells convert fuel and oxidant into electricity and a reaction
product. Fuel cells that employ hydrogen as the fuel and oxygen as
the oxidant, for example, produce water and/or water vapor as the
reaction product.
[0005] The inventors herein have determined that conventional fuel
storage devices, especially those used in conjunction with fuel
cells, are susceptible to improvement. More specifically, the
inventors herein have determined that it would be desirable to
provide fuel storage devices that can precisely control the flow of
fuel to the fuel cell. The inventors herein have also determined
that it would be desirable to provide fuel storage devices that are
capable of preheating the fuel and heating byproduct that enters
the storage device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Detailed description of embodiments of the inventions will
be made with reference to the accompanying drawings.
[0007] FIG. 1 is a plan view of a fuel cartridge in accordance with
an embodiment of a present invention.
[0008] FIG. 2 is a plan, partial section view of the fuel cartridge
illustrated in FIG. 1 with a full fuel storage area.
[0009] FIG. 3 is a plan, partial section view of the fuel cartridge
illustrated in FIG. 1 with an empty fuel storage area.
[0010] FIG. 4 is a plan, partial section view of a heat exchanger
in accordance with an embodiment of a present invention.
[0011] FIG. 5 is a partial section view of a connector arrangement
in accordance with an embodiment of a present invention in a
disconnected state.
[0012] FIG. 6 is a partial section view of the connector
arrangement illustrated in FIG. 5 in a connected state.
[0013] FIG. 7 is a perspective view of a notebook computer in
accordance with an embodiment of a present invention.
[0014] FIG. 8 is a schematic block diagram of a notebook computer
and fuel cartridge in accordance with an embodiment of a present
invention.
[0015] FIG. 9 is a schematic block diagram of an electrochemical
cell device in accordance with an embodiment of a present
invention.
[0016] FIG. 10 is a partial plan view of a fuel cartridge in
accordance with an embodiment of a present invention.
[0017] FIG. 11 is a plan, partial section view of a heat exchanger
in accordance with an embodiment of a present invention.
[0018] FIG. 12 is a partial plan view of a fuel cartridge in
accordance with an embodiment of a present invention.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0019] The following is a detailed description of the best
presently known modes of carrying out the inventions. This
description is not to be taken in a limiting sense, but is made
merely for the purpose of illustrating the general principles of
the inventions. Additionally, although the inventions herein are
discussed in the context of fuel cells and host devices powered by
fuel cells, the fuel cartridges described herein are not limited
solely to use with fuel cells. With respect to fuel cells, the
present inventions are applicable to a wide range of fuel cell
technologies, including those presently being developed or yet to
be developed. Thus, although various exemplary fuel cartridges are
described below with reference to direct methanol fuel cells, other
types of fuel cells, such as solid oxide fuel cells and hydrogen
fuel cells, are equally applicable to the present inventions. It
should also be noted that detailed discussions of fuel cell
structures, the structures of other fuel consuming devices, and the
internal operating components of host devices powered thereby that
are not pertinent to the present inventions have been omitted for
the sake of simplicity.
[0020] As illustrated for example in FIGS. 1-6, a fuel cartridge
100 in accordance with one embodiment of a present invention
includes a housing 102, a fuel storage area 104 and a byproduct
storage area 106. Fuel F exits the fuel cartridge 100 by way of a
connector 108 and byproduct B enters the cartridge by way of a
connector 110. It should be noted that, as used herein, the word
"byproduct" is used to refer to the byproduct of the fuel cell
reaction and, in some instances, any unused reactants that may
require storage. The connectors 108 and 110, which mate with
corresponding connectors 109 and 111 (FIGS. 5, 6 and 8) that are
associated with the host device or fuel cell (or other fuel
consuming device), also act as caps to prevent fuel, byproducts or
other materials from exiting or entering the housing 102 unless the
connectors have mated in the manner described below. The exemplary
cartridge 100 is also provided with a fuel heater 112 that heats
the fuel F as it exits the fuel cartridge. The fuel heater 112 in
the exemplary embodiment is a heat exchanger that receives heat H
from the associated fuel cell (or other fuel consuming device) by
way of a connector 114 and transfers the heat to the fuel F in the
manner described below with reference with FIG. 4.
[0021] The exemplary fuel cartridge 100 and the portion of the host
device that receives the fuel cartridge may have corresponding
shapes and a mechanical keying apparatus (not shown), such as a
rail and slot arrangement, to prevent the fuel cartridge from being
inserted improperly and, in many instances, prevent the wrong type
of fuel cartridge from being connected to the host device. A
suitable locking device, such as springs (not shown) that engage
the exemplary retention elements 116, may also be provided to hold
the fuel cartridge 100 in place. Additionally, a relatively small
fuel cartridge 100 (as compared to the host device) could be
inserted into the host device, while relatively large fuel
cartridges could be mounted on the exterior.
[0022] The volume of fuel storage area 104 may be initially
maximized and the volume of the byproduct storage area 106 may be
initially minimized so that the amount of fuel stored in the
cartridge 100 may be maximized for a given housing size. As the
fuel is transferred to and consumed by the associated fuel cell,
the volume of the storage area 104 decreases. The volume of the
byproduct storage area 106 increases in order to accommodate the
byproduct from the reaction at the fuel cell. The overall volume of
the housing 102 should be sufficient to hold a full volume of fuel
prior to use, the combined volumes of the fuel and byproduct as the
fuel is being consumed, and a full volume of byproduct after the
fuel has been completely consumed. As such, the overall volume of
the housing 102 will depend primarily on the fuel consumed by the
fuel cell and the associated fuel/byproduct ratio. The specific
type of fuel will, of course, depend on the fuel cell being fueled.
Although the present inventions are not limited to any particular
fuels or fuel cells, suitable fuels include, for example, methanol
for a direct methanol fuel cell, butane or other hydrocarbons for a
solid oxide fuel cell, and borohydride for a hydrogen fuel cell.
The fuel may also be stored within the housing 102 in a liquid
state or a gaseous state.
[0023] In the exemplary implementation illustrated in FIGS. 1-6,
the fuel storage area 104 is defined by a flexible fuel container
118, while the byproduct storage area 106 is defined by a flexible
byproduct container 120. An outlet tube 122, which is connected to
the connector 108 by way of the fuel heater 112, extends into the
flexible fuel container 118 so that fuel within the fuel storage
area 104 can flow out of the exemplary cartridge 100. Similarly, a
portion of connector 110 extends into the flexible byproduct
container 120 so that byproduct can flow into the byproduct storage
area 106. Alternatively, a single flexible container that is
divided into separate fuel and byproduct volumes by a movable wall
located within the container may be employed. As illustrated for
example in FIGS. 2 and 3, the flexible containers 118 and 120
should each have a large enough maximum volume to occupy perhaps
all of the interior of the housing 102 and, when emptied, occupy
only a small portion of the housing interior. This allows the
flexible containers 118 and 120, either individually or in
combination, to occupy as much as the entire interior of the
housing over the life of the cartridge 100.
[0024] Referring to FIG. 4, and as noted above, the fuel heater 112
transfers heat received from the associated fuel cell (or other
fuel consuming device) to the fuel as it exits the exemplary
cartridge 100. More specifically, the fuel heater 112 in the
exemplary embodiment has an inlet that is connected to the fuel
container 118 and an outlet that is connected to the connector 108.
The exemplary fuel heater 112 is a heat exchanger that includes a
housing 124 and a heat pipe 126. The heat pipe 126, which in the
illustrated embodiment is a solid aluminum rod, includes a portion
128 that extends at least partially through the connector 114. Heat
pipe portion 128 may be brought into thermal contact (and, in the
illustrated embodiment, physical contact) with a corresponding heat
pipe 130 that extends from the associated fuel cell. The heat pipe
130 may be heated at the fuel cell by, for example, bringing the
heat pipe into thermal contact with heat sink fins that extend from
the fuel cell electrodes. The heat pipe 126 (and/or heat pipe 130)
may, alternatively, be any other device that is capable of
transferring heat from the fuel cell to the fuel heater 112. A
plurality of heat transfer fins 132 are connected to the heat pipe
126 and a plurality of walls 134 are positioned between the heat
transfer fins. The inner surface of the housing 124, the heat
transfer fins 132 and the walls 134 together define a fuel path
136. Fuel from the fuel storage area 104 is heated by the heat pipe
126 and fins 132 as the fuel travels through the fuel path 136 on
its way to the connector 108. Portions of the heat pipe 126, heat
pipe 130 and/or heat transfer fins 132 that may come into contact
with fuel can be coated with plastic or other non-reactive material
to prevent corrosion and premature fuel reaction with the metal
surfaces.
[0025] There are a number of advantages associated with the
aforementioned fuel heater. For example, preheating the fuel may
increase the overall efficiency of the system. The present fuel
heater also eliminates the need for external fuel heaters (i.e.
fuel heaters that are associated with the fuel cell or host
device).
[0026] Other types of fuel heating arrangements may also be
employed. By way of example, but not limitation, heated byproduct
from the associated fuel cell may be run through a heat exchanger
to provide heat for the fuel prior to entering the byproduct
storage area 106. Such a fuel heater may be used instead of, or in
combination with, the exemplary fuel heater 112. Turning to FIG.
10, a resistive fuel heater 113 may also be employed. The exemplary
resistive fuel heater 113 may be powered by a battery that is
associated with the fuel cell or host device (typically during fuel
cell startup) and, to that end, an electrical connector 115 is
provided. Alternatively, the resistive fuel heater 113 may be
powered by the fuel cell itself. In either case, the resistive
heater may also be used post-startup to heat fuel as it exits the
fuel cell in the manner described above.
[0027] The exemplary fuel cartridge 100 is also provided with a
pressurizer to increase the pressure within fuel storage area 104.
The pressure may be raised to a level that causes fuel to flow to
the fuel cell, thereby eliminating the need for a fuel pump in the
fuel cell or host device. The required fuel flow is typically
proportional to the electrical current being consumed by the device
the fuel cell is intended to run. Any suitable mechanism may be
used to pressurize fuel storage area 104. In the embodiment
illustrated in FIGS. 1-6, the pressurizer is in the form of a
spring 138 (note FIGS. 2 and 3) that drives fuel from the fuel
storage area 104. Although the spring 138 is a bow spring that
provides a substantially constant force, any suitable spring may be
employed.
[0028] The spring 138 (or other pressurizer) may be positioned at
any suitable location within housing 102. In the illustrated
embodiment, the spring 138 is positioned within the flexible
byproduct container 120 and pushes against the inner surface 120a
thereof. Positioning the spring 138 in this manner causes an
increase in pressure within the fuel storage area 104, and a
decrease in pressure within the byproduct storage area 106, as
compared to what it would be without the spring. Increasing
pressure within the fuel storage area 104, as noted above, drives
fuel through fuel heater 112 and out of the cartridge 100.
Decreasing the pressure within the byproduct storage area 106 helps
draw byproduct into the cartridge 100 and helps prevent byproduct
from leaking out of byproduct storage area 106 by creating
backpressure across the connector 110. Typically, there is a
one-to-one correspondence between the decrease in volume of the
fuel storage area 104 and the increase in volume of the byproduct
storage area 106.
[0029] A movable wall 140 is positioned between the fuel and
byproduct containers 118 and 120 in the illustrated embodiment. The
movable wall 140 is generally rigid and acts as a pressure
distribution mechanism that distributes the spring force evenly
across the associated wall of the flexible fuel container 118.
Although the movable wall 140 may be any suitable size, the
exemplary movable wall is large enough to distribute the force
generated by the spring 138 evenly across the entire side of the
flexible fuel container 118. As illustrated for example in FIG. 2,
the spring 138 is in a compressed state when the fuel storage area
104 is full. As fuel exits the flexible fuel container 118, the
spring 138 expands, thereby driving the wall 140 through the fuel
storage area 104. This decreases the volume of fuel storage area
104 and increases the volume of the byproduct storage area 106. The
spring 138 is in a more extended state, as illustrated for example
in FIG. 3, when the fuel container 118 is empty.
[0030] It should be noted that the present inventions are not
limited to such an arrangement. For example, the movable wall may
be omitted depending on the pressurizer scheme. The movable wall
140 may also be replaced with a pair of generally rigid plates
positioned within the flexible inner container 120 on opposite
sides of the spring 138. The plates may be attached to the spring
138, to the interior walls of the flexible inner container 120, or
may float freely between the spring and the walls. Additional
details concerning the flexible fuel containers 118 and 120, the
spring 138, and the movable wall 140 are provided in U.S.
application Ser. No. 10/000,249 (Pub. No. US 2003/0082427 A1),
which is assigned to the Hewlett-Packard Company.
[0031] The movable wall 140 may also be used in a fuel level
indicator arrangement to allow the user to determine how much fuel
is in the fuel cartridge 100. Referring to FIG. 1, the housing 102
may be provided with a window 142 through which a small portion of
the movable wall 140 is visible. The housing 102 also includes
indicia 144 that is located at positions which correspond to the
position that the movable wall 140 is in at various times during
the useful life of the cartridge 100. For example, when the fuel
storage area 104 is full (FIG. 2), the movable wall 140 is aligned
with the "Full" indicia and when the fuel storage area is empty
(FIG. 3), the movable wall is aligned with the "Empty" indicia.
[0032] The exemplary fuel cartridge 100 also includes a metering
device for precisely controlling the flow of pressurized fuel
through the connector 108. As illustrated in FIG. 4, the exemplary
fuel cartridge 100 includes a valve 146 that is located between the
connector 108 and the downstream end of the fuel path 136. The
valve 146, which can be any suitable device that is capable of
controlling the flow of fuel, is operable between a fully open
state which allows maximum fuel flow, a fully closed state that
allows no fuel flow, and a plurality of states therebetween that
allow the fuel to flow at various rates between no flow and full
flow in the illustrated embodiment. The exemplary valve 146 is
controlled with electrical signals that are received by an
electrical connector 148 on the exterior of the housing 102. The
host device may include a corresponding electrical connector 149
(FIG. 8) that allows valve control signals from the host device to
be transmitted to the valve 146. The valve 146 may, alternatively,
be configured to be controlled by a mechanical device. Here, the
electrical coupling may be replaced by a mechanical coupling. The
host device typically controls the valve 146 based on the level of
the electrical load. Alternatively, valve control may be based on
fuel pressure measured at the fuel cell or other types of
performance based feedback. Valve control may also be accomplished
by a controller that is carried by the fuel cartridge itself.
[0033] A wide variety of electrical, mechanical and
electromechanical valves may be used to meter the fuel. Such valves
include, but are not limited to, diaphragm valves, solenoid valves,
bimetallic strip valves, positive pressure valves, umbrella valves,
poppet valves and duckbill valves.
[0034] The location of the valve or other metering device may also
be varied, so long as it is an integral part of the overall fuel
cartridge. For example, the metering device may be located within
the outlet tube 122 or at some other position upstream of the
heater 112. In those instances where a heater is omitted from the
fuel cartridge, the metering device may be located within the
housing or within the connector 108 near the inlet end.
[0035] Although the present inventions are not limited to any
particular arrangement for the connection of the fuel cartridge to
the host device, the exemplary arrangement is a self-sealing
connector arrangement that prevents leakage. With such a
self-sealing arrangement, seals are maintained at the fuel
cartridge 100 and the host device when the two are connected to,
and disconnected from, one another as the fuel cartridge is
received by, and removed from, the host device. Once the sealed
connection is made, fuel is allowed to flow from the fuel storage
area 104 to the fuel cell or other fuel consuming device, and
byproduct is allowed to flow into the byproduct storage area 106,
under the conditions described below. The connection may occur
automatically when the fuel cartridge 100 is received by (e.g.
inserted into or connected to) the host device to connect the fuel
cartridge to the associated fuel consuming device.
[0036] One example of a self-sealing connector arrangement that may
be used in conjunction with the present inventions is illustrated
in FIGS. 5 and 6. The arrangement includes the aforementioned fuel
connector 108 and host device connector 109. The byproduct
connector 110 and corresponding host device connector 111 (FIG. 8)
have the same configuration in the illustrated embodiment.
Additionally, instead of connecting the fuel cartridge to the host
device, the fuel cell or other fuel consuming device may be
provided with its own connectors so that the fuel cartridge can be
connected directly thereto.
[0037] The exemplary connector 108 includes a hollow cylindrical
boss 150 having an inwardly projecting edge 152 and lumen 154 that
opens into the fuel heater 112. The end 156 includes a compliant
septum 158 with a slit 160 that is secured by a crimp cap 162. A
spring 164 (or other biasing device) and a sealing ball 166 are
positioned between the compliant septum 158 and the inwardly
projecting edge 152. The length of the spring 164 is such that the
spring biases the sealing ball 166 against the septum 158 to form a
seal. The end 168 of the crimp cap 162 includes an opening that is
aligned with the septum slit 160.
[0038] The exemplary host device connector 109 includes a needle
170 having a closed end 172, a lateral hole 174, and a bore that
extends from the lateral hole axially through the needle. A sliding
collar 176, which surrounds the needle 170 and is biased by a
spring 178 (or other biasing device) against an annular stop 180,
includes a compliant sealing portion 182 and a substantially rigid
retaining portion 184. The compliant sealing portion 182 includes
an exposed upper surface 186 and an inner surface 188 in contact
with the needle 170. In the disconnected position illustrated in
FIG. 5, the hole 174 is surrounded and sealed by the sealing
portion inner surface 188. The host device connector 109 may also
be provided with a tapered lead-in portion 190 that guides and
centers the fuel cartridge connector 108 as it moves into the
connected position illustrated in FIG. 6.
[0039] When the fuel cartridge connector 108 is inserted into the
host device connector 109 (FIG. 6) in order to establish a
connection between the fuel cartridge 100 and the host device, the
closed end 172 of the needle 170 will pass through the septum slit
160. The septum 158 should be compliant enough to allow the needle
170 to be inserted without large insertion forces. As the needle
170 passes through the septum 158 into the cylindrical boss 150,
the septum surface 186 seals against the crimp cap surface 168
prior to the ball being dislodged. The sliding collar 176 and
sealing ball 166 will be urged in opposite directions until the
hole 174 is exposed. This establishes communication between the
fuel cartridge 100 and the host device. Additional details
concerning the exemplary connector arrangement illustrated in FIGS.
5 and 6 may be found in U.S. Pat. No. 6,015,209, which is assigned
to the Hewlett-Packard Company.
[0040] Turning to materials, and although the exemplary housing 102
may be formed from any suitable material, the choice of materials
will typically depend on the environment that will surround the
housing. The exemplary housing illustrated in FIGS. 1-6 includes
the flexible containers 118 and 120 and, accordingly, does not need
to be formed from a material with any particular resistance to the
fuel and byproduct (though it may still be desirable to use
chemically resistant materials to contain a leak more effectively).
Suitable materials include, for example, polyethylene,
polypropylene, polyethylene terephthalate, polystyrene blends and
copolymers, PEEK, polysulfone, and polymer blends and copolymers of
these materials. It should be noted that in some implementations,
the housing 102 will not be an enclosed container-like structure
and will instead be an open structure that merely defines a space
for fuel and waste storage.
[0041] With respect to the construction of the flexible containers
118 and 120, the containers may be formed from a single-layered
structure or a multi-layered structure, rather than from a
single-layered structure. For example, a three-layer structure
composed of a high-gas barrier layer sandwiched between two
chemically inert outer layers may be employed. Each of these layers
may be made of any suitable materials. The middle layer may, for
example, be formed from a liquid crystal polymer or a polyamide,
which has an extremely low permeability to gasses, and the outer
layers may be formed from a suitable polymer, such as polyethylene,
polypropylene, polystyrene blends or copolymers, PEEK, polysulfone,
and polymer blends and copolymers of these materials.
Alternatively, a metallic outer layer may be added to provide an
additional gas barrier layer and to improve heat transfer between
byproduct storage area 106 and the fuel storage area 104. Another
alternative is a five-layered structure including an inner polymer
layer sandwiched between two metallic layers that are each covered
with a bonding layer that allows the material to be bonded to
itself to form a container. The bonding layer may be formed from
polyethylene or any other suitable material that may be bonded to
itself.
[0042] The flexible byproduct container 120 may include a
super-absorbent material to prevent the byproduct leakage should
the container rupture or the connector 110 fail. The
super-absorbent material in the exemplary embodiment is a material
that is very thin when dry, but can expand to absorb a volume of a
fluid many times greater than the initial volume of the material.
Examples of suitable super-absorbent materials include cross-linked
polyacrylic acid salts, polyvinyl alcohol, poly(2-hydroxyethyl
methacrylate)/poly(ethylene oxide), isobutylene-maleic acid
copolymer derivatives, poly(methacrylic acid) salts,
poly(acrylamide) and polyvinylpyrrolidone. Super-absorbent material
may also be placed at any other desired location within the housing
102 to absorb fuel or byproduct in the event of a fuel or byproduct
container rupture. Also, in addition to super-absorbent materials,
materials such as cellulose sponge materials and standard foams
that are merely absorbent may also be used.
[0043] The internal volume of the housing 102 will, of course,
depend upon the intended application. In a fuel cell powered
notebook computer, incorporating one embodiment of the described
invention, the internal volume of the housing 102 will typically be
250 cc or less. In other applications, such storage devices that
store fuel for portable power supply devices that are powered by
fuel cells, the internal volume of the housing may be 1 L or
more.
[0044] Although the present inventions are not limited to use with
any particular host device, the fuel cell powered notebook computer
200 illustrated in FIGS. 7 and 8 is one example of a host device
having elements that consume electrical power, as well as a device
that generates the electrical power, which may be fueled by the
fuel cartridges described above. Other exemplary host devices
include, but are not limited to, personal digital assistants,
digital cameras, portable telephones and games. The present fuel
cartridges may also be used in conjunction with stand alone power
generators, such as the electrochemical cell described below with
reference to FIG. 9, that may be connected to separate power
consuming devices in order to provide power thereto.
[0045] The exemplary notebook computer 200 is, with respect to many
of the structural and operating components, substantially similar
to conventional portable computers such as the Hewlett-Packard
Omnibook 6000 notebook PC. More specifically, the exemplary
portable computer 200 includes structural components such as a main
housing 202 and a display housing 204 that is pivotably connected
to the main housing by a hinge 206. The main housing 202 includes a
module bay for optional modules such as the illustrated CD-ROM
drive module 208, a 3.5 inch disk drive module, or a ZIP drive
module. The exemplary main housing 202 is also provided with a user
interface 210 that allows the user to interact with the computer
200. The user interface 210 includes a keyboard 212, a touch pad
214, a first pair of right/left click buttons 216 and a second pair
of right/left click buttons 218. Each of these elements operates in
conventional fashion to control the operations of the computer 200
and application programs running thereon. In addition to supporting
a display 220, the display housing 204 also acts as a lid to cover
the user interface 210 when in the closed position. To that end, a
conventional latch arrangement (not shown) may be provided to lock
the free end of the display housing 204 to the main housing 202 and
maintain the display housing in the closed position.
[0046] The operating components of the exemplary computer 200
illustrated in FIGS. 7 and 8 include a CPU (or "processor") 222,
cache and RAM memory 224, a power adapter and fan arrangement 226,
a hard disk drive 228 and a modem 230. The exemplary portable
computer 200 may also include other conventional components such
as, for example, audio and video cards, headphone and microphone
ports, serial, parallel and USB ports, keyboard and mouse ports, a
240-pin PCI connector for docking, an operating system such as
Microsoft.RTM. Windows, and various application programs such a
word processing, spreadsheets, security programs and games.
[0047] The exemplary notebook computer 200 also includes a fuel
cell system 232, or other fuel consuming/power generating device,
that is connected to various electrical loads within the computer.
The exemplary fuel cell system 232 is a fuel cell stack consisting
of a plurality of cells as well as fuel, oxidant and byproduct
manifolds. Although the present inventions are not limited to any
particular type of fuel cell system, the exemplary fuel cells are
direct methanol fuel cells. Fuel from the cartridge 100 is supplied
to the anode and oxygen supplied to the cathode. In the illustrated
embodiment, oxygen may be supplied to the fuel cell stack by
drawing ambient air into the stack through a vent in the housing
202. A fan may be provided to facilitate this process. The
byproducts of the fuel reaction (including water and CO.sub.2, in
the case of direct methanol) are carried away from the fuel cell
and directed to the byproduct outlet connector 111. The notebook
computer 200 or other host device should also include a battery 234
to provide power prior to the initial transfer of fuel to the fuel
cell system 232. Such power would be used to, for example, power
the system processor prior to the production of power by the fuel
cell system 232. During operation of the exemplary computer 200,
the CPU 222 will control the valve 146 (by way of the connectors
148 and 149) so that the proper amount of fuel will flow from the
exemplary fuel cartridge 100 to the fuel cell system 232.
[0048] The present inventions also have application in the area of
electrochemical cell devices, such as fuel cells and batteries,
which may be used to power devices that consume electrical power
(e.g. notebook computers, personal digital assistants, digital
cameras, portable telephones and games). As illustrated for example
in FIG. 9, an electrochemical cell device 300 in accordance with
one embodiment of a present invention includes a housing 302, a
fuel cartridge 100', an electrochemical cell stack 304 which
receives fuel from the fuel cartridge and oxygen from ambient air
that enters the housing by way of a vent, and a pair of contacts
306 and 308 that connect the stack to the host device. The
electrochemical cell stack 304, which may be any suitable stack,
will typically include a plurality of fuel cells as well as fuel,
oxidant and byproduct manifolds. The fuel cartridge 100' is
substantially similar to the cartridge 100 described above. For
example, the fuel cartridge 100' includes a pressurized fuel
supply, a valve to control the flow of fuel from the cartridge,
byproduct storage, and a fuel heater.
[0049] The cartridge 100' is connected to the stack manifolds by
way of a fuel line 108', a byproduct line 110', and a heat
connection 114'. A valve control contact 148' is also provided so
that the host device can control the fuel cartridge valve. The fuel
cartridge 100' may also be either removable or permanently
positioned within the housing 302. In those instances where it is
removable, the fuel cartridge 100' and electrochemical cell stack
304 may be respectively provided with mating connectors, such as
the fuel, byproduct and heat connection apparatus described above
with respect to FIG. 24. It should be noted here that the primary
difference between fuel cells and batteries is simply that all of
the fuel that will be consumed by a battery is initially present in
the battery, whereas fuel cells typically have a replenishable fuel
supply. Thus, the exemplary electrochemical cell device 300 could
also be referred to as a "fuel cell" in those instances where the
associated fuel cartridge 100' is replaceable, or as a "battery" in
those instances where the associated fuel cartridge 100' is not
replaceable.
[0050] There may be instances where it is desirable to add heat to
the byproduct B as it enters the byproduct storage area 106. For
example, heat may be used to prevent the byproduct from freezing,
especially in the vicinity of the inlet, which would prevent
additional byproduct from entering the storage area 106. Turning to
FIG. 11, the exemplary heater 112' illustrated therein is
configured to heat both outgoing fuel F and incoming byproduct B.
The heater 112' is substantially similar to the heater 112 and
similar elements are represented similar reference numerals. Here,
however, the housing 124' is larger and two sets of heat transfer
fins 132 and 132' are connected to heat pipe 126. The heat transfer
fins 132 are on the fuel heating side and the heat transfer fins
132' are on the byproduct heating side, which is isolated from the
fuel heating side. Additionally, the inner surface of the housing
124', the heat transfer fins 132 and 132', and two sets of walls
134 and 134' are used to define the fuel and byproduct paths 136
and 136'. Heat pipe portion 128 may be brought into thermal contact
with a corresponding heat pipe 130 that extends from the associated
fuel cell.
[0051] As noted above with reference to FIG. 4, fuel F from the
fuel storage area 104 is heated by the heat pipe 126 and fins 132
as the fuel travels through the fuel path 136 on its way to the
connector 108. Similarly, byproduct B will be heated by the heat
pipe 126 and fins 132' as it travels from the connector 110",
through the byproduct path 136', to the inlet tube 122'.
[0052] It should also be noted that cartridges in accordance with
the present inventions may be configured such that the fuel and
byproduct are heated by separate heaters, only the byproduct is
heated, and/or a resistive heater or other type of heater is used
to heat the byproduct. To that end, an exemplary fuel cartridge
with a resistive heater 113' that is used to heat fuel as it exits
the cartridge and byproduct as it enters the cartridge, is
illustrated in FIG. 12.
[0053] Although the present inventions have been described in terms
of the embodiments above, numerous modifications and/or additions
to the above-described embodiments would be readily apparent to one
skilled in the art. By way of example, but not limitation, the
various components of the exemplary fuel cartridges described above
may be interchanged. It is intended that the scope of the present
inventions extend to all such modifications and/or additions.
* * * * *